Trouble in paradise as WestJet aircraft within 40ft of sea

1907
June 06, 2018
WestJet 737-800  Picture: Westjet
Photo: WestJet

Reduced visibility and inadequate flight path monitoring allowed a WestJet aircraft to dip within 40ft of the sea as it approached the famous Princess Juliana International Airport on the Carribean island of St Maarten in 2017, an investigation has found.

A Transportation Safety Board of Canada (TSB)  report found that Boeing 737-800, flying from Toronto with 158 passengers and six crew on board,  encountered an unexpected rain shower shortly after passing the missed approach point on March 17.

The aircraft had deviated to the left and was on a steeper than normal angle of descent that the crew did not notice until a ground proximity warning sounded.

They initiated a missed approach 0.30 nautical miles (555m)  from the runway threshold when the aircraft was 40 feet above the water. The aircraft landed safely after a second approach.

The report found the runway lights and visual guidance system had been set at a low intensity and the shower had obscured the view of the airport, limiting the visual references available to the crew.

It said the aircraft emerged from the shower about 1nm (1.85km)  from the runway and the crew realized had been tracking toward an incorrect visual reference, a hotel situated to the left of the runway.

At this point, the aircraft was 190 feet above the water and descending at 940 feet per minute rather than 320 feet above the water on a standard three-degree angle of descent.

Now able to see the actual runway, the crew recognized that the aircraft had deviated to the left of the inbound final approach course, but they were not immediately able to assess their height above water.

The pilot flying advanced the throttles and began to correct the course but the aircraft continued to descend.

It was 63 feet above the water when the aircraft’s enhanced ground proximity warning system (EGPWS) issued an aural alert of “Too low, terrain”. A second alert sounded as it passed from 54 feet to 49 feet.

The crew started the go-around at 40ft, with the lowest recorded altitude at 39 ft.

“The sudden and unexpected poor visibility during the final approach increased the flight crew’s visual workload and led to inadequate altitude monitoring,’’ the report said. “The crew did not notice that the aircraft had descended below the normal angle of descent to the runway threshold until the enhanced ground proximity warning system issued an alert.”

As a result of the incident, WestJet made changes that included a corrective action plan with information for pilots regarding possible challenges and threats on approaching and landing at Princess Juliana International Airport.

READ: Video shows how close Air Canada came to disaster.

The St Maarten event occurred a few months before a high-profile July 7 incident in which an Air Canada Airbus A320 lined up on a crowded taxiway at San Francisco International Airport. The A320 dropped down to 59ft before it started to climb during a go-around.